1. Field of the Invention
The invention relates to methods and apparatus for the synthesis of peptides and oligonucleotides.
2. Brief Description of Related Art
Proteins play a decisive role in practically all biological processes such as enzymatic catalysis, transport and storage, coordinated movement, mechanical supporting function, immune protection, conduction of nerve stimuli and control of growth and differentiation. Proteins are made up of one of more linear polypeptide chains. Their multifarious functions are achieved through three-dimensional folding and the association of these chains. The folding and 3D structure is determined by the primary amino acid sequence of the chains. The multiplicity of protein structures in nature is produced by combining twenty amino acid components. Short partial sequences (oligopeptides) can to a certain extent imitate the local structure and function of a sequence in the total protein formation. Oligopeptides in turn can be prepared by chemical syntheses. Synthetic oligopeptides are thus an important aid in the analysis of the structure and function of proteins.
Because of the size and complexity of proteins, very many peptides are used in systematic studies. For example, localisation of a functional region within a relatively long protein chain using overlapping peptides (cf. M. Z. Atassi, Eur. J. Biol. 145, 1-20 (1984); H. M. Geysen, R. H. Meloen and S. J. Barteling, Proc. Natl. Acad. Sci. U.S.A. 81, 3998 (1984). Also, deciphering the amino acid residues which are essential for function by means of substitution analysis (cf. R. A. Houghton, Proc. Natl. Acad. Sci. U.S.A. 82, 5131 (1985); H. M. Geysen, R. H. Meloen, and S. J. Barteling, Proc. Natl. Acad. Sci. U.S.A. 81, 3998 (1984).
Biological test reactions such as enzymatic reaction and antibody binding are very sensitive, so that even small quantities (ng to .mu.g) of peptide substrates are sufficient. For the rapid and simple implementation of such tests it is advantageous if the peptide substrate is immobilized on a solid support material and can be readily removed from the reaction solution. The reaction with the peptide can then be measured quantitatively either in the remaining reaction solution or by subsequent analysis of the support-bound material.
The extent to which such systematic investigations can be carried out depends essentially on the speed of the peptide synthesis and on the technical and the chemical characteristics of the support. Rapid peptide syntheses can be carried out according to the principle developed by Merrifield of step-wise synthesis on a solid phase (R. B. Merrifield, J. Amer. Chem. Soc. 85, 2149 (1963)).
A process will be described below by which very many (several hundred) immobilized oligopeptides can advantageously be prepared per working day in quantities adequate for test purposes and on a suitable support material or flat material.